aa FORESTRY IN 



obtained between the operations of geodesy and those of 

 topography. 8. Construction of geographic maps. 



For instruction in topography and geodesy, and for use 

 in practical exercises in both departments, the school con- 

 tains, writes Signor Castel, abundant material, acquired 

 for the greater part with funds supplied by the State. 

 Grouping the articles vith a view to a brief description of 

 them, they may be classed together in the following 

 order : 



Apparatus for use in the direct measurements of distance. 

 Chains, tape measures, similar measures made of elastic 

 steel, levels, and graduated rulers. 



Apparatus for use in the indirect measurement of distances. 

 A. Lugeol micrometer, Ertel's telemeter, longi meter, eye- 

 glasses of the tacheometer, and of the olometric theodolite 

 of Porro ; mobile estadias ; Groetar's apparatus. 



A ngle-determining instruments. Quadrants, pantometers, 

 grafometers, box compass, Burnier's compass, level with 

 vertical arc, Ladois' level, Linglae"s level ; sight, with 

 reflection by Porro ; Kater's compass, Cugnot's planchette 

 or circumferenter, French planchette, German planchette 

 of Lehman, planchette perfected by Ertel and Starke ; 

 quadrant with sights, with eye-glass, with eye-glass and 

 level, with an arc of a circle ; declinator used in dialling, 

 copper compass, reflecting mirror, quadrant with two eye- 

 glasses ; graphic sextant, another with two eye-glasses, 

 pocket sextant ; Porro's sextant, reflecting by prisms with 

 water-level ; the same, with sights and one eye-glass ; 

 Porro's octant of reflection and graphic prism ; Douglas's 

 circle of reflection ; artificial horizon ; theodolites on 

 system of Richer, Spanish theodolite, German theodolite 

 of Breithaupt, theodolites of Troughton, Pastorelly, 

 Evererest; Trough ton's repeater; Brunner's theolodite of 

 the third order, Brunner's of the second order ; Troughton's 

 great zeni-azimutal circle; Gaus's heliotrope. 



Instruments used in levelling. Mason's level, water level, 

 level with prism and perpendicular, clisimetres of Burel 

 and of Mayer, levels of Chairgrasse, levels with sights, 



